High speed circuit interrupter



Aug. 11, 1931a w, HERDEN 1,818,801

HIGH SPEED CIRCUIT INTERRUPTER Filed Jan. 18, 1930 Inventor: Wilhelm Herden,

8 Q His Attorney.

Patented Aug. 11, 1931 UNITED STATES PATENT ounce WILHELH HERD, O! BEBLIIT-HEBIBDORI, GERMANY, ABBIG-NOR TO GENERAL ELEG- TRIG COKPANY, A CORPORATION 01' NEW YORK 1mm srnnro cmcurr m'rnnncrmn Application filed January 18, 1930, Seriallo.

My invention relates to circuit controlling I devices and has for its princi a1 object to increase the operating speed t ereof.

In the case of large switches for heavy '3 duty circuits, relative! great masses must moved rapidly. T is is especially true with quick acting circuit interrupters, of

the type shown in the 'lritle Reissue Patent No. 15,441. The acceleration of the switch 10 parts of such a circuit interrupter takes place by means of strong springs, which, after a sufiicient weakening of a magnetic holding force in response to predetermined co; 'tions such as overload, rapidly move ....tch parts into the disconnected posi Now the quicker this has to take place, onger and larger must the holding be. Together with this s ring rece, the holdi magnet, rowever, ence another :orce, which occurs the pressing together of the cone so-called contact pressure.

special objects of the invention tion. i

till

loot spring tension and the contact pres its used as a power accumulator, employed for the acceleration of the switch parts. According to the inthis is effected by inteiposingi; be-

mass such as the armature of the elecnomegnet which holds the switch in the connected position and the switch parts to he accelerated, an elastic member which is emerged to produce an impact and thereby an increased accelerating 'eiiect.

A. constructional example of the invention is represented diagrammatically in the drawings. Fig. 1 shows the power accumulater in the loaded condition with the switch closed. Fig. 2 shows it in the unloaded condition with theswitch open.

The switch lever a which is the member to be operated quickly is arranged so as tobe rotatable about the point 6. The switch is maintained in the closed position under normal load conditions by means of the holding force of the magnet a exerted on the armature '0 which has considerable mass, in op osition to which the force of spring 61 and t e pressure force of contact spring 5 sect arrangement which enables not of the force exerts ture mass c until turning moment due smaller than the clockwise turning moment 421,828, and in Germany Kay 25, 1928.

act to bias the switch to the open position. Between the point of engagement 7' of the spring at and the point of engagement of the armature mass 0 of the holding magnet with the switch lever a the power accumulator sprin g with the. impact members h are locate The manner of working of the arrangement is as follows:

In the closed position of the switch as shown in Fi .l a condition of equilibrium prevails in t e lever system. Thus the sum of the tor lies actin about the point e is zero, and t e switch lever o; remains at rest. In this condition, the tension force of s ring i must counterbalance the torque or the olding magnet, as well as the contact pressure and the impact members it are drawn e distance apart 2' due to tensioning the spring 9'.

Assuming that the closing movement of the switch 18 efiectecl by moving the excited gnet must be moved inrther by the amount of the gap a between the impact memhers it than would have been the case if the sprino' g had not heen used. The work accomplished in this ccse. namel the prodon the magnet c and the distance i is accumulated the systern. When the spring-d becomes free to eifiect the cutting-out movement the accumulated power 1s again made serviceable. Thus when the holdingforce of the magnet 82 is reduced in r'spons-e to overload conditions by the r winding a, a resulting unbalance of the mo ments acting on switch lever 68. occurs. At first the spring acts to accelerate the armatore mass 0, o the holding magnet. This results in the gap 2' becomin smaller. "During the shortening of gap-z the arm a and the point 7 remain substantially at rest due to the force required to accelerate the armathe counterclockwise to spring 9 becomes due to the spring forces 0 and cl. As soon.- as unbalance occurs, however, the po nt f also commences to move. Thereby the dis-, connecting movement. of the switchlever a predetermined 7, e

movement of the member ems is started which as long as a gap exists between the impact members h 18 efiected with an acceleration which corresponds to the difierence of the clockwise and counterclockwise turning moments. a

At the moment when the impact members come together, that is when the gap 21 disappears, the momentum already acquired by the armature mass of the magnet is immediately transmitted to the remaining movable members of the system, and the further movement of the swltch lever a therefore takes place with of the clockwise moments of spring d and the additional impact force of the magnet armature. With correct adjustment of the individual masses, forces and paths in this arrangement a considerabl more rapid separation of the contacts wil be obtained than would be the case withv the biasing spring 11 actin alone. If time distance curves of the switc arm movement are plotted first without the springs g actin and secondly with the sprin acting an the two curves are compare with one another, it will be found that the second curve shows a slower initial movement, but that after an exceptionally short time the two curves cut one another and for a ath such as in practice is necessary for t e starting and the blowing-out of the are between the switch contacts uite a considerable saving in time is afiecte What I claim as new and desire to secure by Letters Patent of the Unite States' is:

1. In combination, a movable s itch member, a s ring biasing the member to move in one irection, a relatively movable mass mounted for movement into impact with the switch member, a second s ring connected between the member and sai relatively movable mass'for holding the member, against movement by the first spring, and means. for releasing the mass-to be operated by said second spring into impact with the switch member and thereby accelerate the by the first spring. 2. In combination, a switch member movable between two circ 't controlling positions means for biasing the member to one EOSitIOH, a relativel movable mass resi- 'entl connected with said member, and an e ectro onsive device havin means for holdin t e mass with said resihent connection un er strain to maintain the member in the other osition under certain predetermmed con 'tions and for releasing the mass under other predetermined conditions to accelerate the movement controlling member from said other posltlon 1n accordance with its bias.

8. In combination, se araole contacts, an member there or movable through distance before effecting separation of the operating member to effect separation of the full efiect of the circuit contacts, means for biasing the the contacts, an electromagnet having a movable magnetic membe erating member spring member and the celerate the magnetic mom thereof during movement member through thereby increase the contacts.

r for against its bias, and a connection between the magnetic member to acr upon' release of the operating said limited distance an operatin the speed of separation of In witness whereof, I have hereunto set my hand this 3rd da of Januar 1930.

HELM imEN.

holding the op Ill 

